Patent application title: Gasket

Abstract:

A gasket commonly used for a plural kinds of objective members to be
sealed, the objective members having the same outer shapes and
differently figured plural bores to be sealed. The gasket comprises a
metal base plate, a compound layer made of a synthetic resin or of a
rubber material mixed with a fiber material, the compound layer being
integrally laminated on at least one surface of the metal base plate, a
plurality of openings commonly used for the differently figured bores, a
plurality of bead structures of a chevron-type full-bead commonly used
for the differently figured bores, the plurality of bead structures being
provided around each of the opening, and a recessed groove portion formed
along and opposite side to the bead structure, the recessed groove
portion being formed with an auxiliary sealing portion at a crossing part
or at a matching part of the recessed groove portion, into which a
sealing material made of a rubber material or of a synthetic resin is to
be filled, for commonly use of the gasket.

Claims:

1. A gasket commonly used for a plural kinds of objective members to be
sealed, the objective members having the same outer shapes and
differently figured plural bores to be sealed,said gasket comprising:a
metal base plate,a compound layer made of a synthetic resin or of a
rubber material mixed with a fiber material, said compound layer being
integrally laminated on at least one surface of said metal base plate,a
plurality of openings commonly used for said differently figured bores,a
plurality of bead structures of a chevron-type full-bead commonly used
for said differently figured bores, said plurality of bead structures
being provided around each of said opening, anda recessed groove portion
formed along and opposite side to said bead structure, said recessed
groove portion being formed with an auxiliary sealing portion at a
crossing part or at a matching part of said recessed groove portion, into
which a sealing material made of a rubber material or of a synthetic
resin is to be filled, for commonly use of said gasket.

2. The gasket as set forth in claim 1, wherein said auxiliary sealing
portion of said recessed groove portion is filled with said sealing
material in a manner that the surface formed by filling said sealing
material becomes same as the back surface of said gasket.

3. The gasket as set forth in claim 1, wherein said sealing material is a
silicone rubber.

4. The gasket as set forth in claim 1, wherein said fiber material is made
of a compressible inorganic fiber except asbestos or a compressible
organic fiber.

5. The gasket as set forth in claim 2, wherein said sealing material is a
silicone rubber.

6. The gasket as set forth in claim 2, wherein said fiber material is made
of a compressible inorganic fiber except asbestos or a compressible
organic fiber.

7. The gasket as set forth in claim 3, wherein said fiber material is made
of a compressible inorganic fiber except asbestos or a compressible
organic fiber.

8. The gasket as set forth in claim 4, wherein said fiber material is made
of a compressible inorganic fiber except asbestos or a compressible
organic fiber.

Description:

FIELD OF THE INVENTION

[0001]The present invention relates to a gasket capable of being commonly
used for a plural kinds of objective members to be sealed, the objective
members have the same outer shapes and differently figured plural bores
to be sealed.

PRIOR ART

[0002]Several kinds of gaskets have been used for sealing a contacting
surface and so on between a cylinder block and a cylinder head of an
internal combustion engine. JP-B-6-84785 discloses a gasket material
formed by coating a compound layer including a basic fiber and a rubber
material on a metal plate. Further, JP-A-10-122369 and JP-A-10-122370
disclose a metal gasket in which a full-bead is formed around a
combustion chamber hole and a stopper member made of an elastic rubber
material is filled at a recessed surface side of the full-bead.

[0003]According to the gasket material disclosed by JP-B-6-84785, the
compound layer has superior heat resistance than that made of only a
rubber material, drift and peeling of the compound layer are hardly
caused, the torque retention capacity is improved, and the facility of
embossing process on a metal plate is also achieved. If such a material
is used for the gasket having full-bead structure as shown in
JP-A-10-122369 and JP-A-10-122370, it is served as a superior sealing
gasket appropriate for sealing the above-mentioned contacting surface of
the internal combustion chamber.

DISCLOSURE OF THE INVENTION

Problems to be Solved in the Invention

[0004]According to diversification of product such as upgrading, objective
members to be sealed are recently used in many fields for integrally
fastening via a gasket with a plural kinds of blocks and covers, which
have the same outer shape and a plurality of bores to be sealed which are
slightly different depending on the product specification. In case of
assembling of such an objective members to be sealed, a plural kinds of
gaskets with the same outer shape, having openings corresponding to the
figuration of the bores to be sealed and having a full-bead therearound
are prepared. Appropriate gasket is selected depending on each product
specification and is interposed between the block and the cover to be
fastened integrally in a fastening and assembly line of the members to be
sealed.

[0005]In such a case, a plural kinds of gaskets have to be prepared
depending on the product specification, thereby increasing the cost.
Further, the shapes of such plural kinds of gaskets are similar (their
outer shapes are the same), so that gaskets may be selected by mistake in
case of assembly. Therefore, some identification means should be taken in
order to clear the difference thereof in an assembly site. The
above-mentioned prior arts do not intend to provide a gasket capable of
being commonly used for a plural kinds of objective members to be sealed
with different product specification, so that its drastic improvement has
been highly desired.

[0006]The present invention is proposed in view of the above-mentioned
problems. The object of the present invention is to provide a gasket
capable of being commonly used for a plural kinds of objective members to
be sealed having the same outer shapes and differently figured plural
bores to be sealed.

Means to Solve the Problem

[0007]The gasket of the present invention is a gasket commonly used for a
plural kinds of objective members to be sealed, the objective members
having the same outer shapes and differently figured plural bores to be
sealed. The gasket comprises a metal base plate, a compound layer made of
a synthetic resin or of a rubber material mixed with a fiber material,
the compound layer being integrally laminated on at least one surface of
the metal base plate, a plurality of openings commonly used for the
differently figured bores, a plurality of bead structures of a
chevron-type full-bead commonly used for the differently figured bores,
the plurality of bead structures being provided around each of the
opening, and a recessed groove portion formed along and opposite side to
the bead structure, the recessed groove portion being formed with an
auxiliary sealing portion at a crossing part or at a matching part of the
recessed groove portion, into which a sealing material made of a rubber
material or of a synthetic resin is to be filled, for commonly use of the
gasket.

[0008]According to the present invention, the auxiliary sealing portion of
the recessed groove portion is preferably filled with the sealing
material in a manner that the surface formed by filling the sealing
material becomes same as the back surface of the gasket. Further, the
sealing material is preferably a silicone rubber, but other rubber
material or a synthetic resin may be used. Still further, the fiber
material is preferable made of a compressible inorganic fiber except
asbestos or a compressible organic fiber.

EFFECT OF THE INVENTION

[0009]The gasket of the present invention is composed of a metal base
plate and a compound layer made of a synthetic resin or a rubber material
mixed with a fiber material, the compound layer being integrally formed
by laminating on at least one surface of the metal base. The compound
layer has a superior heat resistance, and in addition the drift of the
rubber material or the synthetic resin each constituting the compound
layer or peeling thereof from the metal base plate are hardly caused when
the gasket is interposed to be integrated between two objects to be
sealed. Further, the gasket has an improved torque retention capacity and
a superior right quality. In addition, emboss process facility is
provided by the metal base plate and a bead structure integrally formed
with the compound layer is easily achieved, thereby obtaining a superior
shape retention capacity. Further provided are a plurality of openings
and a plurality of bead structures with full-bead structure both of which
can correspond to a plurality of bores to be sealed and can be commonly
used for the different figuration of the bores to be sealed, so that one
gasket can be used for a plural kinds of objective members to be sealed
which have the same outer shape and have differently figured bores to be
sealed. Therefore, it does not need to prepare a plural kinds of gaskets
depending on the product specification in an integrally assembly
procedure, thereby achieving low cost. In addition, the selection mistake
is prevented during assembly so that special identification means is not
required at the assembly site.

[0010]Further, an auxiliary sealing portion is provided by filling a
sealing material made of a rubber material or a synthetic resin at a
crossing part or a matching part formed accompanied with common use of a
recessed groove formed along and opposite to the bead structure. Although
a part of bead structure or recessed grove is designed to face the inside
of the bore without being fastened and compressed under the condition
that the gasket of the present invention is interposed to be fastened,
the auxiliary seal part is provided at the crossing part or the matching
part following the recessed groove, so that the flow of liquid passing
through the bore along the recessed groove is blocked to prevent the
liquid from leaking in and flowing out the other portions, thereby
appropriately keeping the sealing ability of each bores to be sealed.

[0011]If the auxiliary seal portion formed by filling the sealing material
is provided in such a manner that the surface becomes the same face with
the surface opposite to the bead structure, the gap between the sealing
surface and the objective member to be sealed is eliminated, so that the
liquid along the recessed groove can be surely blocked. Further, if the
sealing member is made of a silicone rubber, it is easily filled and has
a superior adhesion ability to the objective member, thereby achieving
accurate sealing of the filled portion. Still further, the silicone
rubber is superior in the heat resistance and the chemical resistance,
thereby being preferably used. If the fiber material is made of a
compressible inorganic fiber other than asbestos or a compressible
organic fiber, the characteristic of the compound layer is applied to
obtain the sustention of sealing ability and the safeness of handling.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a diagrammatic plane view showing one embodiment of the
gasket of the present invention.

[0013]FIG. 2 is a back side view of the gasket.

[0014]FIG. 3 is a fragmentary sectional view along the line X-X in FIG. 1.

[0015]FIG. 4 is a fragmentary sectional view along the line Y-Y in FIG. 2.

[0016]FIG. 5 is a fragmentary sectional view along the line Z-Z in FIG. 2.

[0017]FIG. 6 shows a diagrammatic plane view showing how the gasket is
used.

[0018]FIG. 7 shows another diagrammatic plane view showing how the gasket
is used.

PREFERRED EMBODIMENTS TO EXECUTE THE INVENTION

[0019]Now, the preferred embodiments of the present invention are
explained referring to the drawings. FIG. 1 is a diagrammatic plane view
showing one embodiment of the gasket of the present invention, FIG. 2 is
its back side view, FIG. 3 is a fragmentary sectional view along the line
X-X in FIG. 1, FIG. 4 is a fragmentary sectional view along the line Y-Y
in FIG. 2, FIG. 5 is a fragmentary sectional view along the line Z-Z in
FIG. 2, and FIG. 6 and FIG. 7 show diagrammatic plane views showing how
the gasket is used.

[0020]The gasket G shown in the figure is formed in such a manner that a
compound layer is applied to be integrally laminated on both sides of the
metal base plate 1 such as an aluminum plate or a steel plate like a
stainless steel plate, the compound layer being made of a synthetic resin
or a rubber material mixed with a fiber material made of a compressible
inorganic fiber other than asbestos or a compressible organic fiber and
an additive agent (rubber chemicals, a filling agent or the like), thus
compound layers 2, 2 are formed. The gasket has a plurality of openings 3
as mentioned later and a plurality of bead 4 of full-bead structure
therearound. The compound material of the compound layer 2 in the figure
is mixed with fiber, is imprinted and bonded with pressure by means of a
roller using an adhesive agent on the metal plate, then is vulcanized to
be bonded in an oven, thus obtaining a gasket sheet formed by integrally
laminating the compound layer 2 on both sides of the metal plate 1.
Otherwise, the compound material is formed like a sheet in advance, and
is laminated on both sides of the metal base plate 1, thus obtaining a
similar gasket sheet. The gasket sheet is punched out to form the
above-mentioned plurality of openings 3 to have a desired shape. Before
or at the same time of the punching out, a chevron-type bead 4 and a
recessed groove 5 opposite thereof are formed. Further, a plurality of
fastening bolt holes 6 are formed along the outer shape with appropriate
spaces in case of punching out.

[0024]The gasket G in the figure has three openings 3 (3a, 3b, 3c) and is
formed with a bead structure 4 around each opening 3 and a bolt hole 6
and with a recessed groove 5 opposite to the bead structure. The three
openings 3a, 3b, 3c are formed so as to be capable of being commonly used
for two kinds of objective members A, B to be sealed with differently
figured three bores to be sealed as shown in FIG. 6 and FIG. 7. The
objective members A, B to be sealed are manufactured in such a
specification that they have the same rectangular outer shape, the bores
Aa, Ab, Ac, of the objective member A to be sealed correspond to the
bores Ba, Bb, Bc of the objective member B to be sealed respectively, the
kinds of fluid passing each corresponding bores is the same, their shapes
are similar, however their sizes are slightly different. The bore Aa of
the objective member A to be sealed is a little smaller than the bore Ba
of the objective member B to be sealed, the bore Ab is a little larger
than the bore Bb, and the bore Ac is a little larger than the bore Bc.

[0025]The gasket G is formed so as to be commonly used for two kinds of
objective members A, B to be sealed as mentioned above. Specifically, the
opening 3a approximately corresponds to the size of the bore Aa of the
objective member A to be sealed, the opening 3b approximately corresponds
to the size of the bore Bb of the objective member B to be sealed, and
the opening 3c approximately corresponds to the size of the bore Bc of
the objective member B to be sealed. As the result, the opening 3a
becomes smaller than the bore Ba of the objective member A to be sealed
and the openings 3b, 3c become smaller than the bores Ab, Ac of the
objective member A to be sealed respectively. The gasket G comprises a
rectangular outer frame Ga and a partition frames Gb, Gc forming like a
letter "T" for dividing the inside of the outer frame Ga into three
openings 3a, 3b, 3c. The partition frame Gb constitutes a border between
the openings 3a and 3b and the openings 3b and 3c, and the partition
frame Gc forms a border between the openings 3b and 3c.

[0026]A bead 4 (4a, 4b, 4c) with full-bead structure is provided for the
outer frame Ga and the partition frames Gb, Gc along the circumference of
the openings 3a, 3b, 3c respectively in order to make sure the sealing of
the bores Aa, Ab, Ac, Ba, Bb, Bc. A recessed groove 5 (5a, 5b, 5c) is
formed at the opposite surface (back side) accompanied with the
configuration of the bead 4. Namely, the bead 4a and the recessed groove
5a are annular shaped in a line along the outer frame Ga, and the bead 4b
and the recessed groove 5b are formed in four-line along the partition
frame Gb, and the bead 4c and the recessed groove 5c are formed in a line
along the partition frame Gc. The both ends of four lines of bead 4b and
the recessed groove 5b cross or join the bead 4a and the recessed groove
5a respectively (it is referred as the crossing part M, N hereinafter),
one end of the bead 4c and the recessed groove 5c crosses or joins three
lines of the bead 4b and the recessed groove 5b respectively (it is
referred as the crossing part O), and the other end of the bead 4c and
the recessed groove 5c crosses or joins the bead 4a and the recessed
groove 5a respectively (it is referred as the crossing P), thus keeping
the continuity of the bead 4 and the recessed groove 5.

[0027]Now explained is how the two kinds of objective members A, B are
sealed with the gasket G having the bead 4 and the groove 5 as mentioned
above. FIG. 6 and FIG. 7 diagrammatically show the gasket G is interposed
between the objective surfaces of the members A, B to be sealed so as to
be integrally fastened.

[0028]When the gasket G is used for sealing the member A, the bead 4a and
the two lines of bead 4b at the opening 3a side relate to the sealing of
the bore Aa, and the bead 4a, the two lines of bead 4b at the opening 3a
side and the bead 4c relate to the sealing of the bores Ab, Ac.
Therefore, a part of the partition frame Gb faces the inside of the bores
Ab, Ac, and the two beads 4b and the recessed groove 5b of the partition
frame Gb formed opposite to the opening 3a are exposed to the fluid
passing through the bores Ab, Ac. Accordingly, each fluid may flow into
the neighboring bores Ab, Ac through the recessed grooves 5a or 5c from
the recessed groove 5b which is exposed to the fluid, however, an
auxiliary sealing portion 7 is provided at the recessed groove 5 of the
crossing parts M, N, O as shown in FIG. 2 and FIG. 5, so that the fluid
flow is prevented and there causes no fear that the fluid may flow into
the neighboring bores Ab, Ac through the recessed groove 5.

[0029]When the gasket G is used for sealing the member B as shown in FIG.
7, the bead 4a and the two lines of bead 4b opposite to the opening 3a
relate to the sealing of the bore Ba, and the bead 4a, the two lines of
bead 4b opposite to the opening 3a and the bead 4c relate to the sealing
of the bores Bb, Bc. Therefore, a part of the partition frame Gb faces
the inside of the bore Ba, and the two beads 4b at the opening 3a side
and the recessed groove 5b of the partition frame Gb are exposed to the
fluid passing through the bore Ba. Accordingly, each fluid may flow into
the recessed grooves 5a or 5c from the recessed groove 5b which is
exposed to the fluid, however, an auxiliary sealing portion 7 is provided
at the recessed groove 5 of the crossing parts M, N, O as shown in FIG. 2
and FIG. 5, so that the fluid flow is prevented and there causes no fear
that the fluid in the bore Ba may flow into the part which is not related
to its sealing.

[0030]In this embodiment, in either case of the objective members A, B to
be sealed, the bead 4 and the recessed groove 5 are fastened and
compressed and are not exposed to the fluid in each bore at the crossing
part P, so that an auxiliary sealing portion is not required.

[0031]Accordingly, the gasket G in the figures can be commonly used for
the two kinds of objective members A, B to be sealed having the same
outer shape and bores to be sealed Aa, Ab, Ac, Ba, Bb, Bc with different
figuration. If the objective members to be sealed A, B are randomly
placed on an assembly line depending on the production plan, there is no
fear of attachment of wrong gasket G and no identification means is
required and there is no need of identification means. The auxiliary
sealing portion 7 is provided by filling a sealing material at the
crossing part or the matching part of the recessed groove 5 accompanied
with the formation of the bead 4, so that the fluid is prevented from
entering to a part where liquid is not necessary through the recessed
groove 5. Therefore, the gasket G can be preferably and commonly used for
the two kinds of objective members A, B to be sealed, thereby attributing
the reduction of the production cost of the members A, B.

[0032]The outer shape of the gasket G and the shape, number and figuration
of the opening 3 are not limited to those shown in the figures. They may
be modified according to the shape of the objective member to be sealed
and the figuration of the objective bore to be sealed, and accordingly
the figuration of the bead 4 and the recessed groove 5 may be also
determined accordingly. Further, the crossing part or the matching part
may be varied. The crossing part or the matching part to be provided with
the auxiliary sealing part is reasonably provided considering an expected
flow pass. In this specification, the compound layer 2 is integrally
laminated on both sides of the metal base plate 1, however, it may be
integrally laminated only on a surface where the bead 4 is formed.
Further, the metal base plate 1 is exposed at the outer circumference and
the inner circumference of the gasket G by punching out, however, such a
part may be covered with the compound layer 2. In addition, a graphite
coating layer may be provided on the surface of the compound layer 2 or a
silicone resin coating layer may be provided as an adhesion preventing
membrane.